Combined ship and propeller



May 20, 1930. o -r 1,759,511

GOIBINBD SHIP AND PROPELLER Filed Sept. 20, 1928 Patented May 20,

UNITED STATES PATENT? OFFICE L'UIQWIG I031, 01' HANOVEBIGEBEANY SHIP AND PROPEILEB Application filed September 20, 1888,.8eria1 No. 807,182, and in Germany time 10, 1987.

Pro llers ofships have already been arrange in a kind tunnel provided at the bottom of the hull and extending from the bow to the stern the object of this arrangement being to reduce the resistance which the ship offers and to increase the efficienc The arrangements in question having ecome known up to now have not proved successful owin to the reason that the shapes of the tonne were unsuited for the objects in view.

If, forinstance, the tunnel is cylindrical in transverse section, matters become the reverse of what they ought to be, in that the resistance is increased instead of decreased, owing to the 5 friction arising at the inner wall of the tunnel. If the propeller is arranged, for instance, about in the middle of the longitudinal axis of the tunnel, so that the change of the trans verse section of the tunnel in front of the 2o' propeller, i. e. of that portion of the tunnel ,through which the water is sucked in, is about fthe same as the change of the transverse sectionof the other portion of the tunnel, through which the water is discharged, and if a certain ratio exists between the smallest and the largest sectional area, the tunnel would be strongly conical and the water would flow remote from the inner wall of the tunnel in the dischar e portion of the same, and its 0 velocity woult? not be transformed into ressure, whereas in the suckin portion 0 the tunnel strong friction woul arise.

In contradistinction to all known manners 'of arranging the propeller in the tunnel, I arran e it in the narrowest part of the same, and l design the tunnel which is conical in front of theprop'eller, as well as behind it, in such a manner that the cone in front of the ropeller is short and increases quickly in I 'ameter from-the propeller to the end or,

more precisely, to the commencement of the tunnel, whereas the cone behind the propeller is long and increases only slowly in diameter from the pro ller to itsend. There is, thus, only a sma surface in the front portion and, therefore, also only little friction, and there is afiorded in the rear-portion the possibility to reduce graduall the high speed of the water in this-part of t e tunnel and to 0 convert it into pressure.

It is possible to design the tunnel in this way that the enlargement proceeds chiefly or only 1n horizontal direction, that is to say, not or nearly not also in a vertical one. Constructionalforms of this kind afford the possib1l 1ty to use shi s with tunnels according to the lnventlon a so in shallow water, as the depth of immersion of the ship need not be greater than normally. Concerning, however, ships w1th deep draught, also the reverse may 00 take place, that is to say, the tunnel can be enlarged more in vertical direction than in a honzontal one. Finally, it is also ssible to arrange two or more tunnels side y side, especially with ships for shallow water, so 05 that the draught of the ship is not in the least mcreased.

The invention is illustrated dia ammatis ca11y and by way of example on t e accom-- p anyn 1g drawmg, on which Figure 1 is a side-view of one constructional form of a ship with its tunnel and the propeller there- 1n F gure 2 is a horizontal sectlon through th1s constructional form; Figures 3 and 4 are views similar to Fi s. 1 and 2 and show an- '75 Figures 5, 6 and 7 show three more modifica tions of only the narrowest portion of the tunnel with the propeller therein, to ether with means for driving the propeller; igure 8, which shows a transverse section instead of a longitduinal one, as Fi s. 5-7, shows again another modification, igure 9 is a transverse section through a further modification, andFi e 10 shows also a transverse section, a as fully described herein-. after.

On the drawing, a (Figsel and 2) denotes the hull of the ship, (1 its bow, and 0 its stern. t t denote the tunnel s the pro ller, m the motor, and w the shaft driven y the motor and driving the propeller. The shape of the tunnel in the horizontal plane of its axis appears distinctl from Fig. 2, and it is to be seen from this gure, that, apart from that short portion where there is the pro peller, the cross-section of the tunnel in all other portions is e'nlar solely in horizontal direction. Fig. 2 ows also clearly that the tunnel cone t is short and increases quick- 100 water'throughth'e tunnel. 1 Inthe mo ifi'catio'n shown in Figs. 3 and 4, the-motorm is arrangedabove the tunnel,

' over the rear -partthereof,"and the shaft w is, therefore, arranged obliquely, asis, consequently, also the propeller. In all other respects, matters are the same as before.

In Figs. 5 and 6h denotes a hollow body of stream-line shape which is arranged in the tunnel where this latter is narrowest, and is held in lace by lateral stays I). These stays may be esigned as portions of screw-threads so as to cause the water to circulate in a certain measure. The centre portion in Fig. 5 serves as a bearing for the propeller shaft, and the stay I) are designed as bearings for shafts o provlded at their inner ends with cogwhecls meshing with an intermediate cogwheel afiixed to the propeller shaft. In Fig. 6 the motor m is located in a chamber provided in the body It. The motor may be an electromotor, an internal combustion motor, a turbine, etc. It is a matter of course that the employment of the body entails, a correspondingly larger diameter of the tunnel.

If this cannot be permitted, one or the other of the modifications shown in Figs. 7 and 8 may be used. In Fig. 7 the propeller s is combined with a rim is provided with cogs z meshing with a pinion r secured to the laterally arranged shaft 10, and in Fig. 8, the propeller is combined with a rim 70 having blades a driven by water under pressure admitted through the branch 4 and escaping through the branch u The transverse section shown in Fig. 9 will be clear without a detailed description, and the same will be true of Fig. 10 which shows distinctly that two tunnels are arranged side by side. It is a matter of course that a propeller is rovided in each tunnel. Mention must only e made, with respect to these two modifications, that the ends of the tunnels are not circular, but oblong, as distinctly to be seen in both figures.

I claim:

1. A combined ship and propeller, comprising, in combination with the hull of the ship, a tunnel-forming member provided at its bottom and comprising a short conical front portion, the diameter of which increases quickly in the direction to the respective open end of the tunnel, and a long conical rear portion, the diameter of which increases slowly in the direction to the respective open end of the tunnel, said two portions communicating with one another at their narrow ends and one of them being twoparted; a propeller arranged at the place of communication of said tunnel portions, a motor between the parts of the twoparted tunnel portion, and a shaft connecting said motor and said propeller.

2. A combined ship and propeller, comprising, in combination with the hull of the ship, a tunnel-forming member provided at its bottom and comprisinga short conical front portion, the diameter of which increases quickly in the direction to the respective open end of the tunnel, and a long conical rear portion, the diameter of which increases slowly in the direction to the respective open end of the tunnel, said two portions communicating with one another at their narrow end, a propeller arranged at the place of communication of said tunnel portions, means for supporting the pro eller, and means for driving it, these means Being located near said lace for communication, substantially as set orth.

3. A combined ship and propeller, comprising, in combination with the hullof the ship, a tunnel-forming member provided at its bottom and comprising a short conical front portion, the diameter of which increases quickly in the direction to the respective open end of the tunnel, and a long conical rear portion, the diameter of which increases slowly in the direction to the respective open end of the tunnel, said two portions communicating with one another at their narrow end, a propeller arranged at the place of communication of said tunnel portions,.means for suptive open end of the tunnel, and a long coni-- cal rear portion, the diameter of which increases slowly in the direction to the respective open end of the tunnel, said two portions, communicating with one another at their narrow end, a propeller arranged at the place of communication of said tunnel portlons; a body of stream-line shape arranged in said place of communication, a propeller carried by this body, and means for driving the propeller, substantially as set forth.

A combined ship and propeller, compr1s1ng, in combination with they hull of the ship, a tunnel-forming member provided at its bottom and comprising a short conical front portion, the diameter of which increases qulckly in the direction to the respective open end of the tunnel, and a long conical rear portion, the diameter of which increases slowly in the direction to the respective open end of the tunnel, said two portions communicating with one another at their narrow.end, a propeller arranged at the place of communication of said tunnel portions a body of streamline sha e arranged in said (Flace of communicatlon, a propeller carrie by this body, and means for driving the propeller, these means being located in the said body, substantially as set forth.

In testimony whereof I afiix my signature.

LUDWIG KOBT. 

